I cannot give you the 20c difference, after several hundred stamps
I have yet to find a 20c lithograph.
Here is the twin, the 40c San Martin.
Lithography Top, Typography Below.
Typography will always give you slight errors everywhere due to the viscocity of the ink.
Look at the gentleman's sideburns, the lithograhy is a lot clearer.
Look at the top outer frame between the stamps, and how irregular it is with Typography.
